Example usage for org.apache.commons.collections4.comparators ComparableComparator INSTANCE

Introduction

In this page you can find the example usage for org.apache.commons.collections4.comparators ComparableComparator INSTANCE.

Prototype

ComparableComparator INSTANCE

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The singleton instance.

Usage

From source file:net.sf.jasperreports.crosstabs.fill.calculation.BucketDefinition.java

/**
 * Creates a bucket.// www .  j  av  a  2s  . c  o  m
 * 
 * @param valueClass the class of the bucket values
 * @param orderer bucket entries orderer
 * @param comparator the comparator to use for bucket sorting
 * @param order the order type, {@link BucketOrder#ASCENDING}, {@link BucketOrder#DESCENDING} or {@link BucketOrder#NONE}
 * @param totalPosition the position of the total bucket
 * @throws JRException
 */
public BucketDefinition(Class<?> valueClass, BucketOrderer orderer, Comparator<Object> comparator,
        BucketOrder order, CrosstabTotalPositionEnum totalPosition) throws JRException {
    this.orderer = orderer;
    this.order = order;

    if (orderer == null) {
        // we don't have a bucket orderer
        if (order == BucketOrder.NONE) {
            // no ordering, values are inserted in the order in which they come
            this.bucketValueComparator = null;
        } else {
            // the buckets are ordered using the bucket values
            // if there's no comparator, we're assuming that the values are Comparable
            this.bucketValueComparator = createOrderComparator(comparator, order);
        }
    } else {
        // we have an order by expression
        // we only need an internal ordering for bucket values
        if (Comparable.class.isAssignableFrom(valueClass)) {
            // using natural order
            this.bucketValueComparator = ComparableComparator.INSTANCE;
        } else {
            // using an arbitrary rank comparator
            // TODO lucianc couldn't we just set here bucketValueComparator to null?
            if (log.isDebugEnabled()) {
                log.debug("Using arbitrary rank comparator for bucket");
            }

            this.bucketValueComparator = new ArbitraryRankComparator();
        }
    }

    this.totalPosition = totalPosition;
    computeTotal = totalPosition != CrosstabTotalPositionEnum.NONE || orderer != null;
}

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From source file:net.sf.jasperreports.crosstabs.fill.calculation.BucketDefinition.java

public static Comparator<Object> createOrderComparator(Comparator<Object> comparator, BucketOrder order) {
    Comparator<Object> orderComparator;
    switch (order) {
    case DESCENDING: {
        if (comparator == null) {
            orderComparator = new ReverseComparator<Object>();
        } else {/*from  ww w  . j  a  v  a 2  s .  co m*/
            orderComparator = new ReverseComparator<Object>(comparator);
        }
        break;
    }
    case ASCENDING: {
        if (comparator == null) {
            orderComparator = ComparableComparator.INSTANCE;
        } else {
            orderComparator = comparator;
        }
        break;
    }
    case NONE:
    default:
        throw new JRRuntimeException(EXCEPTION_MESSAGE_KEY_UNSUPPORTED_ORDER_TYPE, new Object[] { order });
    }
    return orderComparator;
}

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